INFO: task syz.1.13:4433 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.13 state:D stack:23952 pid: 4433 ppid: 4184 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x97/0x280 kernel/time/timer.c:1890
do_wait_for_common+0x29a/0x440 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
kthread_stop+0x16e/0x540 kernel/kthread.c:666
ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:263
ext4_fill_super+0x660b/0x9a60 fs/ext4/super.c:5088
mount_bdev+0x287/0x3c0 fs/super.c:1400
legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
vfs_get_tree+0x88/0x270 fs/super.c:1530
do_new_mount+0x24a/0xa40 fs/namespace.c:3034
do_mount fs/namespace.c:3377 [inline]
__do_sys_mount fs/namespace.c:3585 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3562
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7c22067eea
RSP: 002b:00007f7c2028ae68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f7c2028aef0 RCX: 00007f7c22067eea
RDX: 0000200000000040 RSI: 0000200000000080 RDI: 00007f7c2028aeb0
RBP: 0000200000000040 R08: 00007f7c2028aef0 R09: 0000000002000008
R10: 0000000002000008 R11: 0000000000000246 R12: 0000200000000080
R13: 00007f7c2028aeb0 R14: 0000000000000541 R15: 0000200000000000
Showing all locks held in the system:
3 locks held by kworker/0:0/7:
#0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc90000cc7d00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8c1210f0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043
2 locks held by ksoftirqd/1/20:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:3/380:
#0: ffff888016879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000313fd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by udevd/3562:
#0: ffff8880202fa118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#1: ffff888147474468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
2 locks held by getty/3946:
#0: ffff88802c17d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
1 lock held by syz-executor/4183:
#0: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#0: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845
1 lock held by syz-executor/4195:
#0: ffff88802026a468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
3 locks held by kworker/u4:7/4309:
#0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc90002fafd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8c1210f0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043
1 lock held by syz.1.13/4433:
#0: ffff88807d8360e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by udevd/5014:
#0: ffff8880202fa118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
2 locks held by kworker/0:19/5478:
#0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000407fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
1 lock held by syz.2.326/5665:
#0: ffff88807d8360e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz-executor/5759:
#0: ffff8880202fa118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
2 locks held by syz.3.395/5926:
#0: ffff8880202f1918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#1: ffff88802028b468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4444 Comm: kworker/1:10 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events pwq_unbound_release_workfn
RIP: 0010:remove_class_from_lock_chain kernel/locking/lockdep.c:5913 [inline]
RIP: 0010:remove_class_from_lock_chains kernel/locking/lockdep.c:5952 [inline]
RIP: 0010:zap_class+0x2e5/0x890 kernel/locking/lockdep.c:5997
Code: 3f 4d 85 ff 0f 94 c0 49 83 c7 f8 0f 94 c1 08 c1 75 b5 4d 89 fd 49 c1 ed 03 43 0f b6 44 35 00 84 c0 0f 85 4d 02 00 00 45 8b 27 <41> f6 c4 fc 0f 84 0b 02 00 00 41 c1 ec 08 44 89 e5 01 ed 49 81 fc
RSP: 0018:ffffc9000360fac0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000f5e RCX: 0000000000016b00
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8ef335ce
RBP: 000000000002d650 R08: dffffc0000000000 R09: fffffbfff1fedf85
R10: fffffbfff1fedf85 R11: 1ffffffff1fedf84 R12: 00000000022ec410
R13: 1ffffffff201a018 R14: dffffc0000000000 R15: ffffffff900d00c0
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd99c888ad8 CR3: 00000000636f5000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__lockdep_free_key_range kernel/locking/lockdep.c:6126 [inline]
lockdep_unregister_key+0x330/0x500 kernel/locking/lockdep.c:6328
wq_unregister_lockdep kernel/workqueue.c:3518 [inline]
pwq_unbound_release_workfn+0x262/0x2b0 kernel/workqueue.c:3756
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287